Conduit or pipe and process of treating the same.



P. MGILROY.

CONDUIT OR PIPE AND PROCESS OF TREATING THE SAME.

APPLICATION FILED 11.22. 1914.

mg ys Patented Dec. 15, 1914.

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CONDUIT OR PIPE AND PROCESS OF TREATING THE SAME. APPLICATIONILEDAPKQ2.1U1-L 1 129,731 a Patented Dec. 15,1914;

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IPETER MQILBGY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T ENAMELEDMEET-AIS COMPANY, OF SHABPSBUBG, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA CONDUIT 0B PIPE AND PROCESS OF TREATING THE SAME.

incense Specification of Letters Patent.

Patented Dec. 15, 1914i.

Application filed April 22, 1914. Serial No. 833,791.

To all whom it mar concern Be it known that 1, PETER MoILnoY, a citizenof the United States, and resident of Pittsburgh, North Side, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Improvement in Conduits or Pipes and Processes of Treating theSame; and I do hereby declare the following to be a full, clear, andexact description thereof.

My invention relates to coated pipes, and to the treatment of enameledcoated pipes for use as electrical conduits for contannng electric Wiresand for other purposes.

In the manufacture of coated pi es for electrical conduits, the pipe iscleanec to remove scale and slag therefrom, then the ends of the pipearethreaded, then a threaded coupling or fitting is placed on one ofsaid ends and it projects beyond said end. The pipe is then coated withenamel by dipping, then dried to finish same, which dipping and dryingare repeated so that it is ready for shipment and use. Another length ofpipe is adapted to be connected to such projecting end of and successivelengths can be connected in like manner.

The object of my invention is to provide a cheap and novel manner oftreating coated metal pipes wherein the projecting threaded end of thecoupling of the pipe is protected from the coating or ename into whichthe same is dipped, and thus prevent said coupling threads from beingfilled up or choked with the coating fluid, While a further ob ject ofthe invention is to provide a protector for the exposed threads of theconduit coupling Which will securely inclose the same and which can bevery quickly applied before coating and can be very quickly removedvvhen the conduit is finished or at the point Where the conduit is to beused.

A still further object of my invention is to provide a conduit couplingin which its exposed threaded end Will be clean so that the threadsthereof will not need to be cleaned before the same can be used inconnecting up with the threaded end on another conduit, Which Will thusmake good electrical connection with such next succeeding conduit, andthus overcome the objections to open circuits Where a good connection isnot made between the successive lengths of the some.

the coupling by its threaded end To these ends my invention consists,generally stated, in the novel method and article, as hereinafter morespecifically set forth and described, and particularly pointed out inthe claims.

To enable others skilled in the art to which my invention appertains toconstruct to practice my improved method and produce my improvedconduit, I will describe the same more fully referring to theaccompanying drawing, in Which:

Figure 1 is a longitudinal sectional view of the threaded pipe ready fortreatment. Fig. 2 is a like view of the pipe before treatment and withthe coupling and'its protector applied. Fig. 3 is a like view of thesame after coating. Fig. l is a side view of the pipe after theprotector has been removed. Fig. 5 is a perspective view of theprotector employed. Fig. 6 is a longitudinal sectional view of thethreaded pipe be fore treatment showing one threaded end having theprotector applied, and coupling attached to the other end. Fig. T is alike view of the same after coating. Fig. 8 is a like view of the sameafter the protector has been removed. Fig. 9 is a perspective view ofthe protector employed in Figs. 6 and 7.

Like symbols of reference herein indicate like parts in each of thefigures of the drawing'.

In practice, for the purpose of carrying out my invention, the pipe 1 isusually submerged in a weak solution of acid, preferably sul luric, toremove slag or scale and the pipe is then removed and if necessary as insome processes, the surfaces of the same are subjected to a blast of aircontaining abrading material, such as sand. This sand blast process isfor the urpose of removing the slag and scale whic ha ve been left afterthe pickling process and after this step such surfaces are left smoothand well adapted for the reception of the coating 2, which is generallyformed of different materials, one form being known as enamel coating.This enamel coating 2 is applied either by dip ping the pipe 1 into afluid bath of such coating, or any other suitable way, after which thepipe is baked or air dried in order to harden said coating. Ifnecessary, two or more coatings may be applied in order to get thedesired results, and the manner of applying such coats may be performedby dipping the pipe perpendicularly or hOl'lthe usual metal fitting orcoupling 4: is

placed on one of said threaded ends, by its threaded interior surface 4'with a ortion ofthe same projecting beyond said end,

while such projecting portion is provided I with a protecting sleeve 5which fits within the same over the threaded surface on such portionand'itsinner end abuts against said threaded 'pipeinsaid coupling. Thissleeve 5 is formed of any suitable material, such as -paper, linen,pulp, metal, wood, or card- A board, and it is of a sufficient length toextend from the end of the pipe 1 within the coupling 4, over thethreads of such coupling beyond said pipe end to cover the same'and .canextend beyond said coupling if desired. The sleeve 5 will be also ofsuch diameter as will fit closely or snugly over the exposed threadedend of the coupling 4 and if desired such sleeve when made of suitablematerial can be of such a diameter" to be forced laterally in thecoupling by a slight pressure, or can be sprung therein and held byexpanding, or made of such asi'ze so that when turned therein it will socause the threads on such end to take slightly into said sleeve. It willbe evident that when the pipe 1 has the coating 2 applied thereto thatsuch coating will be applied on the exterior of the pipe and coupling aswell as upon the interior of the pipe and protecting sleeve 5,-

and the material of such coating will also tend to assist in forming aconnection between the pipe and sleeve by entering the 40 joint or spacebetween the inner end of such sleeve and pipe end in the coupling,while, if desired, the sleeve can be made loose enough to allowsufficient or a small amount of enamel to reach the threads in theprojecting portion of the coupling to prevent their rusting. When thepipe is ready to be shipped the protecting sleeve can be pulled out ofthe coupling in any suitable manner, 'andsuch sleeve retained forfurther treatments of pipe, if desired, or such sleeve can remain inthe, coupling until it is ready for use and then withdrawn Theadvantages of my invention will be apparent to those skilled in the artsince 5 the threads on the projecting portion of the coupling pipe willbe thus retained in the original condition as to shape and size, andthey will be protected by the protecting sleeve, so that such pipe willreach the consumer in such shape that the threads on such portion andprotected to prevent their rusting or being damaged and the pipe andcoupling will be ready for instant use in coupling when received orbysimply pulling out the protecting sleeve,or when a fragile sleeve isused by slitting or cutting the sleeve longitudinally to remove the samethereby leaving the threads clean to be used. The particular solutionused for loosening the scale may be changed or varied, as Well as themanner of applying the same on said blast, and one or more coatin s ofthe enamel may be applied to the plpe, while the material composing andmanner of applying and removing the protector can be changed, andvarious othermodifications and changes in the steps or in the articleproduced by my invention may be resorted to without departing from thespirit of'the invention or sacrificing any of its advanta es.

ractical experience with the method herein described has produced a muchcleaner and more finished article than under the ordinary method informing such pipe, as well as a great saving in the cost of manufactureand loss of pipe, while the cleaning of the threads on the couplingbefore they can be used in coupling will be overcome, and a much betterarticle obtained than has been heretofore possible. The pipe thus formedwill reduce the contractors cost very materially, as well as a greatsaving in 'labor, and if thus made will eliminate the cleaning of thethreads in the coupling with dies, etc., in order to use the same inconnecting up the pi e thereto. It will also be seen in Figs. 6, 8 and 9that the other threaded end 3 of the pipe lfrom that used by theprotected couphng 4 may also be provided with a protecting sleeve 5'over they threads, so that in such case the ordinary exposed threads oneither or both the coupling and pipe end may be protected in coating andthereby not only have the threads in the projecting end on the couplingkept clean but also the threads on the opposite end of the pipe.

What I claim as my invention and desire to secure by Letters Patent is:11

1. The process of treating a. conduit unit having a threaded portion,consisting in the steps of applying a protecting sleeve to cover saidthreaded portion, and then applying acoating over said unit and saidsleeve.

2. The process of treating a conduit unit having a threaded portion,consisting in the steps of applying a fragile protecting sleeve to coversaid threaded portion, and then applying a coating over said unit andsaid sleeve.

10 duit unit having a threaded portion, a fragile protecting sleevecovering said threaded portion, and a protecting coating over and unitand sleeve.

In testimony whereof, I the said Pmnn MCILROY have hereunto set my hand.

PETER. MQILROY. Witnesses: l

T.B'.H' J. N. Coon.

